Alcohol use and abuse is prevalent among adolescents. Alcohol remains to be the primary drug of choice among this population. However, due to ethical considerations, it is impossible to investigate the effects of adolescent alcohol exposure in the human population. Therefore, animal models must be utilized to examine the effects of alcohol exposure during this developmental period. Recent preliminary data from our laboratory suggests that exposure to alcohol during adolescent development attenuates the adult's initial response to ethanol-induced ataxia. In addition, preliminary results from our laboratory suggest that adolescent alcohol exposure exacerbates the alcohol withdrawal response in adulthood. The overall objective of this proposal is to investigate more fully whether exposure to alcohol during the adolescent period will alter the pharmacological response to alcohol in adulthood. Specifically, the proposed work will examine the effect of adolescent alcohol exposure on (1) the adult's initial response to the intoxicating effects of alcohol, (2) the development of rapid tolerance to the intoxicating effects of alcohol, (3) the development of chronic tolerance to the ataxic and hypothermic effects of alcohol, and (4) the severity of the alcohol withdrawal reaction. Specific aim 1 will address the sensitivity of these responses to the level of intoxication achieved during adolescence. The second specific aim will examine whether exposure to alcohol during early, middle, and late periods of adolescent development will result in differential effects on the adult response to alcohol. Specific aim 3 will investigate whether the pattern of alcohol exposure (i.e., chronic versus intermittent) will differentially alter the adult response to alcohol. Findings from these studies will significantly characterize the effects of the dose, timing, and pattern of alcohol exposure during adolescence on later responsiveness to ethanol in adulthood. This requisite characterization of adolescent developmental alcohol effects, coupled with the known ontogeny of neural systems during the adolescent period, should lead to further investigation of possible alcohol-induced perturbations of the developing central nervous system which may underlie an altered adult response to alcohol.